Survey on Use of Surface Sensitive Radiances
The Radiative Transfer and Surface Property Modeling Group at the 14th International TOVS meeting called for a focus on surface emissivity. The group set actions to enlighten the community on the methods and state of the problem in this area. One of the immediate tasks was to take a survey of operational weather centers and ascertain what surface sensitive channels are now being assimilated. The following table was created from this survey, with the blue “x” (
) where only atmospheric sounding channels are assimilated, and the green “checkmark” (
) denoting where surface sensitive channels are assimilated. The most prevalent surface sensitive channels are from AMSU/A over ocean; often however centers will only assimilate channel four (52.8 GHz on the wing of oxygen absorption) and higher. Active research over land with IR and microwave window channels is underway and this group would like to facilitate the dissemination of workable knowledge which will allow the use surface sensitive radiances.
| Key | ||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| sounding channels only | | surface sensitive channels | P | previously operational | T | operational testing | |||||||
This survey began Jun2005 and was posted Aug2005 (update upcoming Jan2007)
Also available: NWP centers and use of ATOVS
| Skin Temperature | Land | Ocean | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Single | Spectral | HIRS | AIRS | AMSUA | AMSUB | HIRS | AIRS | AMSUA | AMSUB | |||
| BMRC (Australia) | | T | | |||||||||
| CMC (Canada) | | T | | T | | | ||||||
| DWD (Germany) | | | | |||||||||
| ECMWF (Europe) | | | | T | | | | | | |||
| KMA (Korea) | | | | |||||||||
| KNMI (Netherlands) | | T | | T | | |||||||
| JMA (Japan) | | | | |||||||||
| Météo France | | T | T | T | T | | T | |||||
| NRL (USA) | | T | T | T | T | | T | |||||
| NCEP (USA) | | | | | | | | | | |||
| UK-Met Office | | T | T | P | T | | T | |||||
Emissivity References
Infrared Emissivity
Garand, L., M. Buehner, and N. Wagneur, 2004. Background Error Correlation between Surface Skin and Air Temperatures: Estimation and Impact on the Assimilation of Infrared Window Radiances. Journal of Applied Meteorology, 43, No. 12, 1853-1863.
Sherlock, V., 1999. ISEM-6: Infrared Surface Emissivity Modle for RTTOV-6. EUMETSAT NWP SAF , 17pp.
Snyder, W. C., Z. Wan, Y. Zhang, and Y. Z. Feng, 1998. Classification-based emissivtiy for land surface temperature measurement from space. Int. J. Remote Sens., 42, pp. 83-106.
Microwave Emissivity
Deblonde, G., 2000. Evaluation of FASTEM and FASTEM2.Meteorological Service of Canada , 33pp.
Jones, A., and T. H. Vonder Haar, 1997. Retrieval of microwvae surface emittance over land using coincident microwave and infrared satellite measurements. J. Geophys. Res. , 102, pp. 13609-13626.
Karbou, F., C. Prigent, L. Eymard, and J. Pardo, 2005. Microwave Land Emissivity Calculations Using AMSU Measurements IEEE Trans on Geosci and Rem Sens, 43, no. 5, 948-959.
Prigent, C, F. Chevallier, F. Karbou, P. Bauer, and G. Kelly, 2005. AMSU-A Land Surface Emissivity Estimation for Numerical Weather Prediction Assimilation Schemes. Journal of Applied Meteorology, 44, no. 4, 416-426.
Weng, F., B. Yan, and N. Grody, 2001. A microwave emissivity model. J. Geophys. Res., 106, no. D17, pp. 20115-20123.
ISCCP Surface Climatology Data Sets:
including mean monthly and seasonal surface infrared and microwave emissivities
POCs: Benjamin Ruston and Sid Boukabara